Glucagon is a peptide hormone with a central role in the regulation of glucose metabolism, and many disorders, including Type 1 and Type 2 diabetes, are notable for abnormalities in glucagon levels. Both clinical practice and research in this field are hampered by the lack of appropriately specific and sensitive assays for glucagon levels in blood. The goal of this project is to develop and validate improved immunoassays for glucagon determination, using recently made hyperspecific monoclonal antibodies to glucagon. The new capabilities offered by these assays can lead to significant advances in the understanding of glucose homeostasis disorders and, in parallel, enable accurate clinical testing for this crucial hormone.